The present invention relates to an electromagnetic wave device that functions as an amplifier, oscillator, etc. of electromagnetic waves, light waves, etc.
Masers and lasers are two examples of the conventional oscillators operating in the range of electromagnetic or light waves. The operating frequencies or wavelengths of these oscillators are generally fixed at the specific values that are determined by the physical phenomena they are to utilize, and hence are difficult to vary over a broad range. Ordinary transistor oscillators are capable of frequency alterations but are not suitable for use in the ultrahigh frequency range or in the region of light waves.
Devices, such as a traveling-wave tube, that utilize the plasma dispersion of electron beams feature wideband operation, but their frequency range is not so wide as to include the region of light waves. The limited frequency range occurs because the operating principles of the devices require components for signal delaying structure, but such cannot be realized in the wavelength range of light waves.